The provided references don't offer a complete step-by-step guide, but they imply that using voids is the key to cutting nested families in Revit. Here's a breakdown of the general approach and considerations:
Using Voids to Cut Nested Families
The technique likely involves creating a "super void" within the host family that can then cut through elements in the nested family. This approach is useful for creating parametric openings and complex geometry.
Steps (Generalized):
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Create the Host Family: This is the primary family that will contain the nested family and the void.
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Create the Nested Family: Design the family that you want to be cut. This family needs to be loadable.
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Load the Nested Family into the Host Family: Insert the nested family into the host family.
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Create the Void Geometry in the Host Family:
- Within the host family's editor, create a void extrusion, void sweep, void revolve, or other void form that represents the cut you want to make. This void needs to be designed in such a way that it intersects with the geometry of the nested family.
- Consider making the void parametric (e.g., driven by parameters like length and width as suggested in the transcript) so that the cut can be adjusted dynamically.
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Cut Geometry: Use the "Cut" tool (Modify tab > Geometry panel > Cut) to cut the nested family with the void geometry. Select the nested family first, then select the void. This step establishes the cutting relationship.
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Lock Alignments (Important for Parametric Behavior): If you want the cut to adjust properly when parameters are changed, carefully align and lock the void geometry to reference planes or other geometry within the host family. This ensures the void remains properly positioned relative to the nested family. Similarly, if the nested family should resize, align and lock it to reference planes or other geometry.
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Test and Refine: Modify the parameters of the host family (especially those controlling the void) to ensure the cut behaves as expected. Adjust alignments and constraints as needed.
Considerations and Troubleshooting:
- Cuttable Categories: Ensure the nested family's category is set to be cuttable. This is a property of the family category itself. Some categories are inherently non-cuttable.
- Void Visibility: Manage the visibility settings of the void element. It might be desirable to hide the void in certain views or at certain detail levels.
- Family Editor vs. Project Environment: This cutting operation needs to be done within the Family Editor, not in the main Revit project environment. The cut is established within the host family.
- Join Geometry: Avoid joining the nested family to other elements in the host family unless absolutely necessary. Joining can sometimes interfere with the cutting operation.
In summary, cutting nested families in Revit primarily relies on creating voids within a host family and using the "Cut" tool to establish the cutting relationship. Parametric control is achieved through aligning and locking the void to reference planes and setting parameters.
